Operating System: Windows Server 2008 R2 Enterprise
Software: ArcGIS 10.3.1 with SQL Server 2012
I am updating our method for merging parcel boundaries from our SDE database with data copied from the appraiser's database. Rather than a join/export process, I've set up a SQL view that joins the parcel data to a table with a copy of the appraiser's data. The join works, but the resulting feature class is converting true curves to straight lines. Here's a screenshot to illustrate what I'm seeing. The tan polygon is the original parcel feature class and the heavier black line shows the geometry of the same parcel in the SQL view:
Why would the SQL view convert the true curve to a series of straight lines?
My hunch here is that this is caused by the fact that true curves in geodatabases traditionally are stored in a separate table or "CAD" binary field type column as described here (scroll down to the section "Feature classes stored using the Microsoft geometry or geography type in a SQL Server database" , and the CAD side table mentioned there), and that the SQL view, being based on SQL Server backend definition rather than a geodatabase Feature Class object, can not incorporate this data. AFAIK, the base table of the feature class stores a secondary geometry in the form of a "simplified" (maybe better said densified) version of the true curve in the way you describe here: a set of straight lines stored in the Geometry or Geography spatial column. It is this that is likely returned in your spatial view, rather than the true curve stored in the CAD side table.
Of course, SQL Server 2012 introduced native support for at least circular arcs in Geometry and Geography storage, but I doubt if this is yet supported by ArcGIS (maybe reading but probably not editing), as it doesn't fulfill all the needs of parts of ArcGIS (e.g. no bezier curves).
By the way, I encountered these interesting articles related to curves and SQL Server:
New Spatial Features in SQL Server 2012 | Lenni Lobel on SQL Server and .NET Development
Geospatial Support for Circular Data in SQL Server 2012 | Lenni Lobel on SQL Server and .NET Development